Sensor apparatus

ABSTRACT

A sensor apparatus of the present invention is provided with a failure diagnosis circuit for setting as a failure diagnosis object section at least any one of a drive circuit section, a detection device, a detection circuit section and a processing circuit section, determining whether the failure diagnosis object section is normal or abnormal, and outputting a failure detection signal from a second output terminal in the case of determining abnormality. It is configured such that a signal of a value outside a range of a normal output voltage is outputted from the first output terminal in the case of the failure diagnosis circuit determining abnormality of the failure diagnosis object section, thereby to improve reliability under abnormal condition.

FIELD OF THE INVENTION

The present invention relates to a sensor apparatus for use inautomobiles, aircraft, vessels, robots, a variety of other electronicdevices, and the like.

BACKGROUND OF THE INVENTION

A conventional sensor apparatus of this kind is described with referenceto a drawing. FIG. 5 is an electric circuit diagram showing theconventional sensor apparatus.

As shown in FIG. 5, the sensor apparatus includes: drive circuitsections 1A, 1B for outputting drive signals that drive detection device2; and detection circuit sections 3A, 3B for fetching response signalsfrom detection device 2 and outputting the response signals. The sensorapparatus further includes: processing circuit sections 4A, 4B forfetching sensor signals from the response signals and outputting thesense signals from first output terminals 5A, 5B; and failure diagnosiscircuit 6 for outputting a failure detection signal from second outputterminal 7.

At least any one of drive circuit sections 1A, 1B, detection device 2,detection circuit sections 3A, 3B and processing circuit sections 4A, 4Bis set as an object of failure diagnosis and referred to as a failurediagnosis object section. Failure diagnosis circuit 6 determines whetherthe failure diagnosis object section is normal or abnormal, and outputsa failure detection signal from second output terminal 7 in the case ofdetermining abnormality.

As related art document information concerning this application, forexample, Unexamined Japanese Patent Publication No. 2004-301512 (PatentDocument 1) is known. Such a conventional sensor apparatus has had aproblem with improvement in reliability under abnormality occurrencecondition.

Specifically, in the above conventional configuration, even thoughabnormality of the failure diagnosis object section has been confirmedby failure diagnosis circuit 6, outputting of the failure detectionsignal from second output terminal 7 is delayed due to some kind ofdefect, and hence a sense signal determined as one under abnormalcondition may be used for control of a controlled object such as anautomobile. Further, on controlled object side such as an automobile,the sense signal determined as one under abnormal condition may beerroneously used for control of the controlled object due to some kindof defect, thereby causing a problem with improvement in reliability.

SUMMARY OF THE INVENTION

A sensor apparatus of the present invention includes a time pointmeasuring unit for measuring time point information and adding the timepoint information to an output concerning generation of the failuredetection signal outputted from the failure diagnosis object section andan output concerning generation of the sense signal. In the case of thefailure diagnosis circuit determining abnormality of the failurediagnosis object section, a sense signal, made to correspond to thefailure detection signal by means of the time point information, isoutputted as a signal outside a range of a normal output voltage fromthe first output terminal.

With this configuration, it is not necessary for a controlled objectsuch as an automobile to determine whether a sense signal outputted fromthe first output terminal is one during normal condition or duringabnormal condition, which can further reduce the possibility toerroneously use a sense signal under abnormal condition on thecontrolled object side, thereby to seek improvement in reliability.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an electric circuit diagram showing a sensor apparatusaccording to a first embodiment of the present invention;

FIG. 2 is a diagram showing a response signal added with time pointinformation of the sensor apparatus according to the first embodiment ofthe present invention;

FIG. 3 is a diagram showing a failure detection signal added with timepoint information of the sensor apparatus according to the firstembodiment of the present invention;

FIG. 4 is an electric circuit diagram showing a sensor apparatusaccording to a second embodiment of the present invention; and

FIG. 5 is an electric circuit diagram showing a conventional sensorapparatus.

DESCRIPTION OF THE EXEMPLARY EMBODIMENT First Exemplary Embodiment

A description will be given below of a sensor apparatus according to afirst embodiment of the present invention with reference to thedrawings. FIG. 1 is an electric circuit diagram showing a sensorapparatus according to the first embodiment of the present invention.

As shown in FIG. 1, the sensor apparatus according to the firstembodiment includes: first and second drive circuit sections 11A, 11Bfor outputting drive signals; angular velocity detection device 12A andacceleration detection circuit 12B as detection device 12, into whichdrive signals from drive circuit sections 11A, 11B are inputted; andfirst and second detection circuit sections 13A, 13B for fetchingresponse signals from detection device 12 and outputting the responsesignals. The sensor apparatus further includes: first and secondprocessing circuit sections 14A, 14B for fetching sense signals from theresponse signals and outputting the sense signals from first outputterminals 15A, 15B; and failure diagnosis circuit 16 for outputtingfailure detection signals from second output terminal 16A. At least anyone of drive circuit sections 11A, 11B, detection device 12, detectioncircuit sections 13A, 13B, and processing circuit sections 14A, 14B isset as a failure diagnosis object section, and failure diagnosis circuit16 determines whether the failure diagnosis object section is normal orabnormal, and outputs a failure detection signal from second outputterminal 16A in the case of determining abnormality.

When failure diagnosis circuit 16 determines abnormality of the failurediagnosis object section, a signal outside a range of a normal outputvoltage is outputted from each of first output terminals 15A, 15B.

Specifically, when failure diagnosis circuit 16 determines abnormalityof the failure diagnosis object sections, failure diagnosis circuit 16transmits that information to first and second processing circuitsections 14A, 14B. First and second processing circuit sections 14A, 14Bhaving received transmission of the information output values to beoutputted from first output terminals 15A, 15B as values outside therange of the normal output voltage. The information transmitted byfailure diagnosis circuit 16 to each of first and second processingcircuit sections 14A, 14B is hereinafter referred to as an “abnormalvoltage value output order signal”.

With reference to the foregoing “normal output voltage range”, forexample, it means a range of ±1.8V from a 0-point voltage whensensitivity is 6 mV/deg/s and a dynamic range is ±300 deg/s. In otherwords, when the 0-point voltage is 2.5 V±0.15 V, the normal outputvoltage range is from 1.55 to 4.45 V.

With such a configuration, it is not necessary for the controlled objectsuch as an automobile to specifically determine whether sense signalsoutputted from first output terminals 15A, 15B are those during normalcondition or during abnormal condition. This can further reduce thepossibility to erroneously use a sense signal under abnormal conditionon the controlled object side, thus leading to further improvement inreliability.

Further, as shown in FIG. 1, it is configured such that the sensorapparatus is provided with time point measuring unit 17 for measuringtime point information and for adding the time point information tooutputs from the failure diagnosis object sections, and the failuredetection signals and the sense signals are made to correspond to eachother by means of the time point information, thereby allowing furtherimprovement in reliability to be sought.

As a specific example, the case of setting first and second detectioncircuit sections 13A, 13B as the failure diagnosis object sections isdescribed. First, time point measuring unit 17 is electrically connectedto first and second detection circuit sections 13A, 13B, whiletransmitting measured time point information. FIG. 2 is a diagramshowing a response signal added with time point information of thesensor apparatus according to the first embodiment of the presentinvention. FIG. 3 is a diagram showing a failure detection signal addedwith time point information of the sensor apparatus according to thefirst embodiment of the present invention.

As shown in FIG. 2, when response signals (r011 to r998) are outputtedfrom first and second detection circuit sections 13A, 13B, time pointinformation (t01 to t99) are added thereto. The response signals (r011to r998) added with the time point information (t01 to t99) are in thestate of being added with the time point information (t01 to t99) alsowhen outputted as sense signals from first output terminals 15A, 15Bthrough first and second processing circuit sections 14A, 14B shown inFIG. 1. Meanwhile, failure diagnosis circuit 16 determines whether firstand second detection circuit sections 13A, 13B as the failure diagnosisobject sections are normal or abnormal, and outputs failure detectionsignals based upon a result of the determination. When first and seconddetection circuit sections 13A, 13B output information on failuredetection toward failure diagnosis circuit 16, as shown in FIG. 3, timepoint information (t01 to t99) identical to that of the response signal(r011 to r998) is added. The failure detection signal (f011 to f998) isgenerated from information on failure detection in failure diagnosiscircuit 16, and it is in the state of being added with the time pointinformation (t01 to t99) also when outputted.

With such a configuration, the failure detection signals (foil to f998)and the sense signals can be made to correspond to each other in termsof time points by means of the time point information (t01 to t99). Thisenables more accurate outputting of a sense signal determined to be oneunder abnormal condition as a signal of a value outside the range of thenormal output voltage, thereby to seek further improvement inreliability.

In the first embodiment, the description is given using the two devices,angular velocity detection device 12A and acceleration detection device12B, as detection device 12 and also using, as the circuit configurationcorresponding thereto, the configuration having first and second drivecircuit sections 11A, 11B, first and second detection circuit sections13A, 13B, and first and second processing circuit sections 14A, 14B.However, it may be configured such that one detection device 12 isprovided and as a circuit configuration corresponding thereto and onlyeach one drive circuit section, detection circuit section, andprocessing circuit section is provided.

Although detection device 12 is the constitutional requirement of thesensor apparatus in the first embodiment, the present invention can alsobe configured even with detection device 12 provided outside the sensorapparatus. Specifically, the sensor apparatus of the present inventioncan be configured by including a drive circuit section, a detectioncircuit section, a processing circuit section, a failure diagnosiscircuit, and a time point measuring unit, which exchange signals withdetection device 12 provided outside the sensor apparatus.

In the first embodiment 1, the example is described where first andsecond detection circuit sections 13A, 13B are set as the failurediagnosis object sections and the identical portions respectively in theangular velocity detection system and the acceleration detection systemare set as the failure diagnosis object sections. However, it may beconfigured such that non-identical portions respectively in the angularvelocity detection system and the acceleration detection system are setas the two failure diagnosis object sections, as in a case where firstdetection circuit section 13A is set as the first failure diagnosisobject section and second processing circuit section 14B is set as thesecond failure diagnosis object section. In that case, it is necessaryto add common first time point information to both information on asense signal from first detection circuit section 13A and information onfailure detection outputted by first detection circuit section 13Atoward failure diagnosis circuit 16, while it is necessary to add secondcommon second time point information to both information on a sensesignal from second processing circuit section 14B and information onfailure detection outputted by second processing circuit section 14Btoward failure diagnosis circuit 16.

Further, although one portion is set as the failure diagnosis objectsection in each of the angular velocity detection system and theacceleration detection system in the first embodiment, it may beconfigured such that failure diagnosis circuit 16 has a plurality offailure diagnosis object sections. Specifically, for example, failurediagnosis circuit 16 is electrically connected to each of first andsecond detection circuit sections 13A, 13B and first and secondprocessing circuit sections 14A, 14B, and outputs failure detectionsignals of the respective sections. With such a configuration, a failurehaving been undetectable by one failure diagnosis object section can bedetected by the plurality of failure diagnosis object sectionsperforming failure diagnoses, so as to improve the accuracy of failuredetection.

Although the description is given using angular velocity detectiondevice 12A, acceleration detection device 12B and the like in the firstembodiment, other than those, a variety of sensor apparatus such as apressure sensor can also implement the present invention.

Second Exemplary Embodiment

A sensor apparatus according to a second embodiment of the presentinvention is described below with reference to a drawing. It is to benoted that elements having similar configurations to those in the firstembodiment are provided with the same numerals as in the firstembodiment, descriptions thereof are not given, and only differencesfrom the first embodiment are detailed.

FIG. 4 is an electric circuit diagram showing a sensor apparatusaccording to the second embodiment of the present invention. As shown inFIG. 4, the sensor apparatus in the present embodiment includes: drivecircuit sections 11A, 11B for outputting drive signals; angular velocitydetection device 12A and acceleration detection circuit 12B as detectiondevice 12, into which drive signals from drive circuit sections 11A, 11Bare inputted; and detection circuit sections 13A, 13B for fetchingresponse signals from detection device 12 and outputting the responsesignals. The sensor apparatus further includes: processing circuitsections 14A, 14B for fetching sense signals from response signals andoutputting the sense signals; failure diagnosis circuit 16 foroutputting failure detection signals; and output circuit section 18 foroutputting the sense signals from processing circuit sections 14A, 14Band the failure detection signals from failure diagnosis circuit 16 fromoutput terminal 18A by the time division system. At least any one ofdrive circuit sections 11A, 11B, detection device 12, detection circuitsections 13A, 13B, and processing circuit sections 14A, 14B is set as afailure diagnosis object section, and failure diagnosis circuit 16determines whether the failure diagnosis object section is normal orabnormal, and outputs a failure detection signal in the case ofdetermining abnormality.

It is configured such that, when failure diagnosis circuit 16 determinesabnormality of the failure diagnosis object section, output circuitsection 18 outputs as an output of the sense signal a signal outside arange of a normal output voltage.

Specifically, when failure diagnosis circuit 16 determines abnormalityof the failure diagnosis object sections, failure diagnosis circuit 16transmits that information to output circuit section 18, for example,and output circuit section 18 having received transmission of theinformation outputs a value to be outputted from output terminal 18A asa value outside the range of the normal output voltage. The signaltransmitted by failure diagnosis circuit 16 to output circuit section 18is hereinafter referred to as an “abnormal voltage value output ordersignal”.

With reference to the foregoing “normal output voltage range”, forexample, it means a range of ±1.8V from a 0-point voltage whensensitivity is 6 mV/deg/s and a dynamic range is ±300 deg/s. In otherwords, when the 0-point voltage is 2.5 V±0.15 V, the normal outputvoltage range is from 1.55 to 4.45 V.

With such a configuration, it is not necessary for the controlled objectsuch as an automobile to specifically determine whether a sense signaloutputted from output terminal 18A of output circuit section 18 is oneduring normal condition or during abnormal condition. This can furtherreduce the possibility to erroneously use a sense signal under abnormalcondition on the controlled object side, thus leading to furtherimprovement in reliability.

Moreover, as shown in FIG. 4, with a configuration such that an outputterminal with reference numeral 18A, from which the sense signals fromfirst and second processing circuit sections 14A, 14B and the failuredetection signals from failure diagnosis circuit 16 are outputted, isshared and the sense signals and the failure detection signals aredigitally outputted by time division system, it is possible to reducethe number of output terminals, so as to realize reduction in size.

Further, as described in the first embodiment, with a configuration suchthat, as shown in FIG. 4, time point measuring unit 17 for measuringtime point information and adding the time point information to anoutput from the failure diagnosis object section is provided, to makethe failure detection signal and the sense signal correspond to eachother by time point information, it is possible to seek furtherimprovement in reliability.

In other words, with such a configuration, the failure detection signaland the sense signal can be made to correspond to each other in terms oftime points by means of the time point information, enabling moreaccurate outputting of a sense signal determined to be one underabnormal condition as a signal of a value outside the range of thenormal output voltage, thereby to seek further improvement inreliability.

Moreover, in output circuit section 18, with a configuration such thatthe sense signal and the failure detection signal made to correspond toeach other based upon the time point information are outputted ascoupled with each other by the time division system, it is possible toomit processing of coupling the sense signal and the failure detectionsignal made to correspond to each other based upon the time pointinformation on the controlled object side.

In the second embodiment, the description is given using the twodevices, angular velocity detection device 12A and accelerationdetection device 12B, as detection device 12 and also using, as thecircuit configuration corresponding thereto, the configuration havingfirst and second drive circuit sections 11A, 11B, first and seconddetection circuit sections 13A, 13B, and first and second processingcircuit sections 14A, 14B. However, one detection device 12 may beprovided and as a circuit configuration corresponding thereto, only eachone drive circuit section, detection circuit section, and processingcircuit section may be provided.

Although detection device 12 is the constitutional requirement of thesensor apparatus in the second embodiment, the present invention canalso be configured even with detection device 12 provided outside thesensor apparatus.

In the second embodiment, the example is described where first andsecond detection circuit sections 13A, 13B are set as the first andsecond failure diagnosis object sections, and the identical portionsrespectively in the angular velocity detection system and theacceleration detection system are set as the failure diagnosis objectsections. However, it may be configured such that non-identical portionsrespectively in the angular velocity detection system and theacceleration detection system are set as the two failure diagnosisobject sections, as in a case where first detection circuit section 13Ais set as the first failure diagnosis object section and secondprocessing circuit section 14B is set as the second failure diagnosisobject section. In that case, it is necessary to add common first timepoint information to both an output concerning a sense signal from firstdetection circuit section 13A and an output concerning failure detectionoutputted by first detection circuit section 13A toward failurediagnosis circuit 16, while it is necessary to add common second timepoint information to both information on a sense signal from secondprocessing circuit section 14B and information on failure detectionoutputted by second processing circuit section 14B toward failurediagnosis circuit 16.

Although one portion is set as the failure diagnosis object section ineach of the angular velocity detection system and the accelerationdetection system in the second embodiment, it may be configured suchthat failure diagnosis circuit 16 has a plurality of failure diagnosisobject sections. Specifically, for example, failure diagnosis circuit 16is electrically connected to each of first and second detection circuitsections 13A, 13B and first and second processing circuit sections 14A,14B, and outputs failure detection signals of the respective sections.With such a configuration, a failure having been undetectable by onefailure diagnosis object section can be detected by the plurality offailure diagnosis object sections performing failure diagnoses, so as toimprove the accuracy of failure detection.

It is to be noted that, also in the example shown in FIG. 4, the failurediagnosis object section may set one portion as the failure diagnosisobject section in each of the angular velocity detection system and theacceleration detection system, or it may be configured such that failurediagnosis circuit has a plurality of failure diagnosis object sections.With the configuration having the plurality of failure diagnosis objectsections, a failure having been undetectable by one failure diagnosisobject section can be detected by the plurality of failure diagnosisobject sections performing failure diagnoses, so as to improve theaccuracy of failure detection.

Although the description is given using angular velocity detectiondevice 12A, acceleration detection device 12B and the like in the secondembodiment, other than those, a variety of sensor apparatus such as apressure sensor can also be implemented.

As described above, the sensor apparatus of the present invention has aneffect of allowing improvement in reliability under abnormal condition,and is useful in automobiles, aircraft, vessels, robots, a variety ofother electronic devices, and the like.

What is claimed is:
 1. A sensor apparatus, comprising: a drive circuitsection for outputting a drive signal; a detection device, into whichthe drive signal from the drive circuit section is inputted; a detectioncircuit section for fetching a response signal from the detectiondevice, and outputting the response signal; a processing circuit sectionfor fetching a sense signal from the response signal, and outputting thesense signal from a first output terminal; a failure diagnosis circuitfor setting as a failure diagnosis object section at least any one ofthe drive circuit section, the detection device, the detection circuitsection and the processing circuit section, determining whether thefailure diagnosis object section is normal or abnormal, and outputting afailure detection signal from a second output terminal in the case ofdetermining abnormality; and a time point measuring unit for measuringtime point information, and adding the time point information to anoutput concerning generation of the failure detection signal outputtedfrom the failure diagnosis object section and an output concerninggeneration of the sense signal outputted from the failure diagnosisobject section, wherein, in the case of the failure diagnosis circuitdetermining abnormality of the failure diagnosis object section, thefirst output terminal outputs the sense signal, made to correspond tothe failure detection signal by means of the time point information, asa signal outside a range of a normal output voltage.
 2. A sensorapparatus, comprising: a drive circuit section for outputting a drivesignal; a detection device, into which the drive signal from the drivecircuit section is inputted; a detection circuit section for fetching aresponse signal from the detection device, and outputting the responsesignal; a processing circuit section for fetching a sense signal fromthe response signal, and outputting the sense signal; a failurediagnosis circuit for setting as a failure diagnosis object section atleast any one of the drive circuit section, the detection device, thedetection circuit section and the processing circuit section,determining whether the failure diagnosis object section is normal orabnormal, and outputting a failure detection signal in the case ofdetermining abnormality; an output circuit section for outputting thesense signal from the processing circuit section and the failuredetection signal from the failure diagnosis circuit by a time divisionsystem; and a time point measuring unit for measuring time pointinformation, and adding the time point information to an outputconcerning generation of the failure detection signal outputted from thefailure diagnosis object section and an output concerning generation ofthe sense signal outputted from the failure diagnosis object section,wherein, in the case of the failure diagnosis circuit determiningabnormality of the failure diagnosis object section, the processingcircuit section outputs the sense signal, made to correspond to thefailure detection signal by means of the time point information, as asignal outside a range of a normal output voltage.